The 'Miss Potter' actor regularly removes all the hair from his chest to make him look younger and more attractive, but his personal grooming has an unpleasant consequence.
He said in an interview with Britain's Radio 1: "I shave my chest because having it hairy makes me look older. It's sexy when it's smooth. But when I shave it, I sometimes get a rash, which is a nightmare. And my wife gets it too. Having a shaved chest is cool for a day, until it starts growing back." The 35-year-old star is married to French production designer Eve Mavrakis.
In keeping with his hair-free look, Ewan refused to grow a moustache for his role as book editor Norman Warne in 'Miss Potter'.
He explained: "I had to wear a fake moustache and it makes you speak really strange. If you're not careful, it will fall off. We shot this scene in the film where I had to laugh and it ended up looking really awkward, but they left the scene in."